Hi All,

As many of us are, I am tired of load shedding and looking for a hybrid system that will keep on during load shedding as well as to save on my electricity bills (approx. R3500-R4000pm for a family of 5). 

I am considering starting with a 5kw solar and inverter combo system. Solar panels will be 5x425w, Luxpower inverter and Dyness battery. This should power most of the essentials in the house.

 I plan to add to this system over time and add 5kw inverter, battery, and solar panels. Hoping to get to a 10kw eventually.

Just wanted advise on this and your thoughts if this is a good idea or system. I would like to get my Eskom bill down as a first prize. Geyser is my biggest consumption with a family of 5 but also looking to run things off the panels during the day at least (Geyser as well if possible). Advice and thoughts are appreciated. 

Thanks in advance. 

46 minutes ago, Sudique said:

Hi All,

As many of us are, I am tired of load shedding and looking for a hybrid system that will keep on during load shedding as well as to save on my electricity bills (approx. R3500-R4000pm for a family of 5). 

I am considering starting with a 5kw solar and inverter combo system. Solar panels will be 5x425w, Luxpower inverter and Dyness battery. This should power most of the essentials in the house.

 I plan to add to this system over time and add 5kw inverter, battery, and solar panels. Hoping to get to a 10kw eventually.

Just wanted advise on this and your thoughts if this is a good idea or system. I would like to get my Eskom bill down as a first prize. Geyser is my biggest consumption with a family of 5 but also looking to run things off the panels during the day at least (Geyser as well if possible). Advice and thoughts are appreciated. 

Thanks in advance. 

Due to your saving criteria and if budget allows it I would start with a Solis S6. This allows power to be fed to non essentials which is all loads not on the back up side. Then add a 2nd if needs be later. 

This inverter has more control and a CT to prevent export but should one be able to export at a favourable rate you can. The Luxpower mentioned does not have the essential/non essential outputs. 

2nd to this the Deye also lights up. Here I would call the 8kW instead of 2x5kW units as an end state. 

Your only 5x425W can at best provide a saving of R800pm IF you can use all the PV during the day. Normally about 25% of PV is unused. 

Just options for starters. 

Edited March 24, 20242 yr by Scorp007

Thank you.

I will consider the Solis S6 and have a look at the Deye option as well. I do like the Solis S6 system though.

According to my experience deye inverter will be best for up

@Sudique hi, I'm new to solar and I'm in the same boat as you were,we are moving to a new place, Initially I was thinking of a 5kw inverter,5kwh battery and 6-7 455 paneles and upgrade the system later on. My biggest consumer is my electric geyser. For that I was thinking of changing the element to 2kw and running it on solar. Which system did you go with?

@Scorp007 i have been browsing this side and I see Solis is getting some love, are they that good or they have a good marketing team. Im drawn towards the Solis because it's a 6kw and I want to run geyser.

19 minutes ago, Leb7 said:

@Sudique hi, I'm new to solar and I'm in the same boat as you were,we are moving to a new place, Initially I was thinking of a 5kw inverter,5kwh battery and 6-7 455 paneles and upgrade the system later on. My biggest consumer is my electric geyser. For that I was thinking of changing the element to 2kw and running it on solar. Which system did you go with?

@Scorp007 i have been browsing this side and I see Solis is getting some love, are they that good or they have a good marketing team. Im drawn towards the Solis because it's a 6kw and I want to run geyser.

All I know about the 6kW Solis is what the talk of the town is. My pure grid tied mini 4G Solis has worked without missing a single beat for 6 yrs.

You will also see that the current Solis range in hybrid has an exchange warrantee which no other brand offers as far as I know. If faulty they are only repaired back in China. This is a major plus point. You will find all the reviews and comments on this forum from users.

2 hours ago, Leb7 said:

@Sudique hi, I'm new to solar and I'm in the same boat as you were,we are moving to a new place, Initially I was thinking of a 5kw inverter,5kwh battery and 6-7 455 paneles and upgrade the system later on. My biggest consumer is my electric geyser. For that I was thinking of changing the element to 2kw and running it on solar. Which system did you go with?

@Scorp007 i have been browsing this side and I see Solis is getting some love, are they that good or they have a good marketing team. Im drawn towards the Solis because it's a 6kw and I want to run geyser.

I think considering prices for panels. Put as many as you can which they inverter can take. Then at least if you upgrading you only have to do the inverter and battery. You dont have to call out someone for panels again.

4 hours ago, Denns said:

  7 hours ago, Leb7 said:

@Sudique hi, I'm new to solar and I'm in the same boat as you were,we are moving to a new place, Initially I was thinking of a 5kw inverter,5kwh battery and 6-7 455 paneles and upgrade the system later on. My biggest consumer is my electric geyser. For that I was thinking of changing the element to 2kw and running it on solar. Which system did you go with?

After paying lawyers transfer fees the budget is bit tight. What do you suggest I start with? Go 8 or 5kw inverter and how many panels will be sufficient to power a geyser during the day without using the grid. I will be using a gas stove. My current consumption per month is around 350-380Kwh this is based on winter figures with the electric geyser and stove, the geyser was switched on 2 hrs in the morning and afternoon.

31 minutes ago, Leb7 said:

After paying lawyers transfer fees the budget is bit tight. What do you suggest I start with? Go 8 or 5kw inverter and how many panels will be sufficient to power a geyser during the day without using the grid. I will be using a gas stove. My current consumption per month is around 350-380Kwh this is based on winter figures with the electric geyser and stove, the geyser was switched on 2 hrs in the morning and afternoon.

A lot more info is required to give even a close estimate. Which country/province/city or town if in ZA.

A bit of a waste to only want to power the geyser from PV. With battery you can also power quite a bit of your loads after sunset. On this point you need to estimate what % of the 13 kWh a day that you used before getting a gas stove is during the 07h00 to 17h00 period and what after sunset. This is only required if you want to use less grid power during the evening/night.

Using PV for the geyser you can heat during the day and even if it takes 4 hours instead of the current 2 hours it will be without grid but depending on the area winter time in ZA can be a challenge and also cloudy period in the summer rainfall area can on some days limit the PV production to around 20% of a sunshine day. Just keep that in mind. To cater for this some power can be provided from battery to get the water hot.

A short answer would be that a 5 kW could do it for you for the geyser and still a lot of fat above the 2 kW element.

33 minutes ago, Scorp007 said:

A lot more info is required to give even a close estimate. Which country/province/city or town if in ZA.

A bit of a waste to only want to power the geyser from PV. With battery you can also power quite a bit of your loads after sunset. On this point you need to estimate what % of the 13 kWh a day that you used before getting a gas stove is during the 07h00 to 17h00 period and what after sunset. This is only required if you want to use less grid power during the evening/night.

Using PV for the geyser you can heat during the day and even if it takes 4 hours instead of the current 2 hours it will be without grid but depending on the area winter time in ZA can be a challenge and also cloudy period in the summer rainfall area can on some days limit the PV production to around 20% of a sunshine day. Just keep that in mind. To cater for this some power can be provided from battery to get the water hot.

A short answer would be that a 5 kW could do it for you for the geyser and still a lot of fat above the 2 kW element.

Because his budget is tight and LS if he’s in SA is technically a thing of the past. He ca get a good inverter size and panels only. I still think as many panels as he can afford to without a battery.

That will kill at least 70% of his electric bill if he runs geyser, pool pumps etc during the day off the inverter.

Then in 6 months he can buy a battery to take care of the remaining part. Battery is the easiest thing to add on to a PB system.

1 hour ago, Leb7 said:

After paying lawyers transfer fees the budget is bit tight. What do you suggest I start with? Go 8 or 5kw inverter and how many panels will be sufficient to power a geyser during the day without using the grid. I will be using a gas stove. My current consumption per month is around 350-380Kwh this is based on winter figures with the electric geyser and stove, the geyser was switched on 2 hrs in the morning and afternoon.

Judging from your usage, anything over 5kWp of panels will be enough and help during cloudy days and any future increases in energy consumption you may have.

A bit more info on loads would help but if you are willing to skip on the battery for now, try and get an inverter 6kw plus.

This way your panels are future proof and so is your inverter.

do batteries last. Buying small and then replacing parts or adding on is expensive in my opinion, even if you sell the used parts. Just do it right the first time and you won’t regret it.

A 6kw plus inverter and 5kw plus of panels will cover at least 70% of your electricity without a battery. Add a 10kwh battery bank in the future and you should be basically using zero grid.

51 minutes ago, Scorp007 said:

A lot more info is required to give even a close estimate. Which country/province/city or town if in ZA.

A bit of a waste to only want to power the geyser from PV. With battery you can also power quite a bit of your loads after sunset. On this point you need to estimate what % of the 13 kWh a day that you used before getting a gas stove is during the 07h00 to 17h00 period and what after sunset. This is only required if you want to use less grid power during the evening/night.

Using PV for the geyser you can heat during the day and even if it takes 4 hours instead of the current 2 hours it will be without grid but depending on the area winter time in ZA can be a challenge and also cloudy period in the summer rainfall area can on some days limit the PV production to around 20% of a sunshine day. Just keep that in mind. To cater for this some power can be provided from battery to get the water hot.

A short answer would be that a 5 kW could do it for you for the geyser and still a lot of fat above the 2 kW element.

Ooh sorry for not introducing myself properly, i live in limpopo tzaneen where there is plenty of sun even during winter. We are a family of 2 adults and a toddler.

My +-13kwh/day I think mostly came from from geyser before 7am and after 5pm from electric stove/air fryer, geyser,lights and TV,the fridge running all day. During the day maybe twice a week 2 loads I a top loader and 2hrs of ironing. I'm only stressing the geyser because I have seen that it does use a lot of electricity. At the new place going to add garage door and gate to the load.

Edited October 8, 2025Oct 8 by Leb7

If most of your usage is during non sun hours then a battery is needed. The system above looks decent but you need more battery in the future and panels.

If you only want to reduce the bill then it’s a fine system.

Just know if you have a geyser element that 3kw and if you run any load over 1kw your panels won’t be able to supply that load. During the day you will pull from battery and eventually from Eskom.

Panels are going for 1.3k a pop. If you could stretch your budget to 50k you can get about 6kw for the panels if it’s within spec of the inverter.

Edited October 9, 2025Oct 9 by Denns

7 hours ago, Leb7 said:

Ooh sorry for not introducing myself properly, i live in limpopo tzaneen where there is plenty of sun even during winter. We are a family of 2 adults and a toddler.

My +-13kwh/day I think mostly came from from geyser before 7am and after 5pm from electric stove/air fryer, geyser,lights and TV,the fridge running all day. During the day maybe twice a week 2 loads I a top loader and 2hrs of ironing. I'm only stressing the geyser because I have seen that it does use a lot of electricity. At the new place going to add garage door and gate to the load.

This system should provide enough power to heat the geyser during sun periods. The problem lies in the fact that you heat the geyser in periods that their is very little sun in summer and no sun in winter. You will save quite a bit on grid use if you save battery power during the evening in order to use it for the geyser for the early morning heat cycle. But I would install the system shown and the start the journey of managing when you use the power. If you use battery for all other loads than the geyser then perhaps you can still use grid for the early geyser heat cycle. The after 17h heat cycle will be saved as you can use the sun 14h to 17h for the geyser. Ironing and washing can be during sun period of the day.

8 panels a good start. Ensure that you have a transfer switch fitted in order to be able to remove inverter with no wiring changes if needs be.

8 hours ago, Leb7 said:

Ooh sorry for not introducing myself properly, i live in limpopo tzaneen where there is plenty of sun even during winter. We are a family of 2 adults and a toddler.

My +-13kwh/day I think mostly came from from geyser before 7am and after 5pm from electric stove/air fryer, geyser,lights and TV,the fridge running all day. During the day maybe twice a week 2 loads I a top loader and 2hrs of ironing. I'm only stressing the geyser because I have seen that it does use a lot of electricity. At the new place going to add garage door and gate to the load.

Also note the battery specs. I assume you do most of your cooking after 5pm? And even the suggestion made by @Scorp007 to heat your geyser with battery may not work. The recommended discharge current as per your battery specs is 50A. That is 2.4KW.

You will blow right past that with just an oven on or the geyser running and you will very quickly shorten its life.

This is why I recommend if you cant do it right, then just get the inverter and panels and run all your big loads during the day. Or still get the same system but dont attempt to run the geyser or do any kind of cooking that exceeds the 50A from the battery.

You will waste 15k on a battery for nothing. Because even with the battery you wont cover your cooking and during the day with any load running together with the geyser you will pull from the battery again. Either option, battery or no battery you will still not be able to do your cooking at night.

Edited October 9, 2025Oct 9 by Denns

1 hour ago, Denns said:

Also note the battery specs. I assume you do most of your cooking after 5pm? And even the suggestion made by @Scorp007 to heat your geyser with battery may not work. The recommended discharge current as per your battery specs is 50A. That is 2.4KW.

You will blow right past that with just an oven on or the geyser running and you will very quickly shorten its life.

This is why I recommend if you cant do it right, then just get the inverter and panels and run all your big loads during the day. Or still get the same system but dont attempt to run the geyser or do any kind of cooking that exceeds the 50A from the battery.

You will waste 15k on a battery for nothing. Because even with the battery you wont cover your cooking and during the day with any load running together with the geyser you will pull from the battery again. Either option, battery or no battery you will still not be able to do your cooking at night.

@Denns @Scorp007 Cooking will be done on a gas stove. The 13kwh is based on my current consumption at the town house using electric stove and geyser. The only new addition to the load at the new house will definitely be more lights(LED) garage door and gate motor. My load is mostly before 7am and after 5pm. The domestic is left alone and only washing and ironing is done dung the day twice a week so to install a system without a battery I dnt think I will benefit even if I move the evening water heating to pv during the day. when it comes to the battery what else should l look at except DOD and Kwh?

2 hours ago, Scorp007 said:

The problem lies in the fact that you heat the geyser in periods that their is very little sun in summer and no sun in winter. You will save quite a bit on grid use if you save battery power during the evening in order to use it for the geyser for the early morning heat cycle.

The after 17h heat cycle will be saved as you can use the sun 14h to 17h for the geyser.

8 panels a good start. Ensure that you have a transfer switch fitted in order to be able to remove inverter with no wiring changes if needs be.

@Scorp007 I agree with you that the 17h heat cycle can be done during day using pv and the early morning cycle done on grid/battery.

Edited October 9, 2025Oct 9 by Leb7

30 minutes ago, Leb7 said:

@Denns @Scorp007 Cooking will be done on a gas stove. The 13kwh is based on my current consumption at the town house using electric stove and geyser. The only new addition to the load at the new house will definitely be more lights(LED) garage door and gate motor. My load is mostly before 7am and after 5pm. The domestic is left alone and only washing and ironing is done dung the day twice a week so to install a system without a battery I dnt think I will benefit even if I move the evening water heating to pv during the day. when it comes to the battery what else should l look at except DOD and Kwh?

@Scorp007 I agree with you that the 17h heat cycle can be done during day using pv and the early morning cycle done on grid/battery.

Should be fine then. Don't worry about the lights and garage motors. Those are negligible. Most garage motors pull the power directly from the battery. Only the charger, which is typically small works all the time to float and charge the battery.

Just charging and discharging current. Try and keep it to the 50A. To maximise battery lifespan as I assume in the future you may add a second one.

18 hours ago, Leb7 said:

hi, I'm new to solar and I'm in the same boat as you were,we are moving to a new place, Initially I was thinking of a 5kw inverter,5kwh battery and 6-7 455 paneles and upgrade the system later on. My biggest consumer is my electric geyser. For that I was thinking of changing the element to 2kw and running it on solar. Which system did you go with?

If you can afford an 8kW inverter then do that. Mine is 4.6. 20 amps. Sounds a lot if you say it quickly, but the appliances in your kitchen (kettle, microwave, dishwasher etc) can easily add up to more than that and trip the inverter. We had problems at first then started having a rule that if you can see two things on in the kitchen, you can't turn on a third. You will always have those sorts of limits (draw enough and your main municipal breaker will trip) but 8kWh gives you a lot more headroom and thus more flexibility in what you use and when.

If you are planning to expand, then in most cases expanding the battery means getting more of what you already have. I have a FreedomWon 10/8. If I want to expand I have to get another 10/8. I can't add in a 5kWh battery (well, I'm told I can but FreedomWon - who do provide worthwhile support - will wash their hands of it and will not help me set up this abomination). 2 5kWh batteries usually is more expensive than a single 10, but it does mean you can expand in 5k increments.

In my experience over panelling is a good thing as long as you don't go to lengths that your inverter cannot cope with. My system has always charged the battery on a nice clear day. On overcast days it would take longer and sometimes wouldn't get the battery charged by 15:30 by which time the sun is nicely in the West. My panels face N and E. I had the panels beefed up a while back. Took the old N panels and moved them E thus doubling on that string, replaced the 325W panels with newer 650s on the N string (where I am roof space limited). On sunny days there is little difference. On days with an overcast morning or cloud throughout the day I am much more likely to get the battery charged. I have seen it recover to 100% at 15:30 in the afternoon - which would never have happened with the original setup.

Making the most of solar is about the fit between when you produce free electricity (IE when the sun is up) and when you consume electricity. There are only general rules here, like doing as much as you can whilst the sun is up. So heat your water when the sun is up, run the pool pump and the dishwasher when the sun is up, do the ironing when the sun is up. By doing this you leave less for your battery to support whilst the sun is down. The tradeoff is different for each household, but we all find that with a bit of thought & experience we can amend our routines to a degree that doesn't really interfere with our life but does allow us to get a good benefit from our PV system.

RE water heating (I alway say this!) consider a heat pump. It will cost you money and I understand that you are stretched right now, but the heat pump draws less power and heats quicker. Even if you don't have a PV system you can achieve a reduction on your electricity bill with a heatpump, especially if you run it on a timer. A 2kW element doesn't use less energy to heat the water, it just means its drawing less power at any given time - but it will run for longer. Check the thermostat - this is usually set too high. My heat pump will not heat past 60 degrees, and actually that is plenty.

2 hours ago, tony Lampard said:

SOLAR ELECTRIC GEYSER CALCULATIONS

Fortunately an electric heater is a resistive device; that is, it provides opposition to current flow when a voltage is applied to dissipate power in the form of heat.   This means the element in an AC geyser or stove can be connected directly to DC solar PV panels to dissipate power in the form of heat.  The DC is more efficient than the AC and the PV is effectively a variac (the intensity of the sun regulates the power fed to the element). 

Resistive loads take more time for AC than DC to produce the same heat. In a DC circuit the opposition to current flow is simply called resistance. In an AC circuit, resistance is called impedance. That is, impedance, measured in Ohms, is the effective resistance to current flow around a circuit containing both AC resistance and AC reactance.

AC voltage is usually represented as its RMS, or "root mean square," value that has a sinusoidal waveform.   The RMS value can be calculated where VRMS is the RMS value, and Vpeak is the peak voltage.

The RMS value was commonly referred to as the signal's "heating value," owing to the fact that the heat that was dissipated by a resistance was equal regardless of whether the applied voltage was DC or AC.

Another advantage in this Front Of Pipe approach, solar PV panels have a limited short circuit current (usually a rating on the label) and the power is therefore zero because there is no voltage; the same is true for open circuit,  a high voltage but no current so power again is zero.  

The rating of the solar panels is on the label, 500w solar panels e.g.   [1]Maximum Power at STC(Pmax) 500W Optimum Operating Voltage (Vmp) 48.63V.    Low voltage at low solar intensity is an aspect that should be understood but does not necessarily need to be controlled - its a soft load, in other words switching on the geyser when there isn't much solar just ends up poor performance and does not overload the system (you can overload if you feed your geyser AC 220v through your inverter).

Let's start with the basics: an electric heater is a resistive device; that is, it provides opposition to current flow when a voltage is applied. When it does so, it dissipates power in the form of heat. We can calculate how much power a resistive load can handle using an equation. The maximum power the heater can supply is dependent on the current that can be supplied. This current is restricted by the current carrying capacity of the power source but can also be limited by the gauge of the wire. This being said, low-voltage DC heaters will need more current to supply an equal amount of power as a heater that runs on 240V, this is the aspect of lower voltages from the solar panel with off peak lower light intensity compounded by not enough panels (the cause of the poor performance).

 For an existing heater run at a lower DC or AC voltage, you can calculate the new wattage. This does mean connecting the element directly to the PV panel is a soft load – in other words the actual wattage is much lower than the rated wattage when the voltage is low so, although its not efficient, it does not overload the panel. 

This voltage-current ( V-I ) relationship is always linear in a pure resistance. So when using resistors in AC circuits the term Impedance, symbol Z is the generally used to mean its resistance. Therefore, we can correctly say that for a resistor, DC resistance = AC impedance , or R = Z.

The impedance vector is represented by the letter, ( Z ) for an AC resistance value with the units of Ohm’s ( Ω ) the same as for DC. Then Impedance (or AC resistance ) can also be represented by a complex number as it depends upon the frequency of the circuit, ω when reactive components are present. But in the case of a purely resistive circuit this reactive component will always be zero and the general expression for impedance in a purely resistive circuit given as a complex number will be:

Z = R + j0 = R Ω’s

The instantaneous alternating voltage applied to the resistor is given as: v = V_msin(ωt)
While the instantaneous alternating current flowing through the resistor is given as: i = I_msin(ωt)

The effective power consumed by an AC resistance for a whole cycle is equal to the power consumed by the same resistor in a DC circuit. This is because in a purely resistive circuit, v and i are in-phase so the power consumed is never zero.

Many AC circuits such as heating elements and lamps consist of a pure ohmic resistance only and have negligible values of inductance or capacitance containing on impedance.

In such circuits we can use both Ohm’s Law  and Kirchoff’s Law  as well as simple circuit rules for calculating and finding the voltage, current, impedance and power as in DC circuit analysis. When working with such rules it is usual to use RMS values only.

---

[1] Pmax is the maximum rated power output of a solar panel. This is sometimes referred to as nameplate capacity. Vpmax is the maximum voltage the solar panel can produce at the maximum power point. Ipmax is the maximum current the solar panel can produce at the maximum power point.

I came across this on youtube but I didn't pay much attention to it because doesn't seems like a popular option but after this lecture I'm gonna go back watch his video.

Edited October 9, 2025Oct 9 by Leb7

3 hours ago, Leb7 said:

I came across this on youtube but I didn't pay much attention to it because doesn't seems like a popular option but after this lecture I'm gonna go back watch his video.

I looked at that root. Too much trouble imo.

Just heat it from your inverter and when money is right and get a heatpump as suggested. I have the luxury of lots of space and being able to self install my system so I chose the route of extra panels onto a geyser controller. If I wasnt self installing, Heatpump would be my best friend especially if not plans to go offgrid.

50 minutes ago, Denns said:

I looked at that root. Too much trouble imo.

Just heat it from your inverter and when money is right and get a heatpump as suggested. I have the luxury of lots of space and being able to self install my system so I chose the route of extra panels onto a geyser controller. If I wasnt self installing, Heatpump would be my best friend especially if not plans to go offgrid.

You won't look back once you have a heat pump. My heat pump is now running for 14 yrs. Long past it's sell by date. 😀

The high load on the graph is the heat pump that ran for 50min and the 1st time switched on in 3 days so the water was quite cold.

3 old sets of batteries age 3 to 5 yrs old. The battery load of 1.7kwh was from 00h00 last night and none during the day. My peak PV with pump running was about 2.1kw. I only have 3.1kw in PV and the old batteries are about 9kwh in capacity. I have never ran them very low. This morning SOC was at 33% but can be as high as 50% in the morning when the previous night was only heating meals from the freezer. For the 9 days of the month my Grid use is only 3.3kwh. I do all my cooking on a single spiral stove. Some pots that need more power I use my 4 solid plate grid hob. Most cooking is done on my induction plate. My "kettle' is a steel whistle item and I boil on the 1kw setting.

Picture place as it gives more info than one can write in text. System is a 5kW Deye using the whole house on the UPS circuit.

Managing power has been a good past time and it is only a matter of doing some thinking. My day time load is only heat pump, 2 fridges/freezer and battery charging. Washing is done when sun is shining once a week. Ironing is so little in power used I don't even measure it.

59 minutes ago, Scorp007 said:

You won't look back once you have a heat pump. My heat pump is now running for 14 yrs. Long past it's sell by date. 😀

The high load on the graph is the heat pump that ran for 50min and the 1st time switched on in 3 days so the water was quite cold.

3 old sets of batteries age 3 to 5 yrs old. The battery load of 1.7kwh was from 00h00 last night and none during the day. My peak PV with pump running was about 2.1kw. I only have 3.1kw in PV and the old batteries are about 9kwh in capacity. I have never ran them very low. This morning SOC was at 33% but can be as high as 50% in the morning when the previous night was only heating meals from the freezer. For the 9 days of the month my Grid use is only 3.3kwh. I do all my cooking on a single spiral stove. Some pots that need more power I use my 4 solid plate grid hob. Most cooking is done on my induction plate. My "kettle' is a steel whistle item and I boil on the 1kw setting.

Picture place as it gives more info than one can write in text. System is a 5kW Deye using the whole house on the UPS circuit.

Managing power has been a good past time and it is only a matter of doing some thinking. My day time load is only heat pump, 2 fridges/freezer and battery charging. Washing is done when sun is shining once a week. Ironing is so little in power used I don't even measure it.

That’s very nice. 14 yrs service is amazing to be honest.

You have a very nice setup going and seems you have your solar habits down also. It has also become a hobby of mine to be honest.

Heat pump definitely looks to be the best. The cost is a bit high but if you get 10 plus years then it’s worth it.

Thank you for all the valuable information.

Response to @tony Lampard idea above:

I just want to raise a few safety and compliance points for the benefit of anyone considering a similar setup this isn’t meant as criticism, but to make sure people understand the risks and what’s required for a compliant installation.

Standard 230 V AC geyser elements are not designed for DC operation. PV panels produce variable DC voltage and current that change constantly with sunlight. Without proper regulation (MPPT or controller), the element and thermostat can be exposed to uncontrolled current and voltage. This can result in overheating, premature element failure, or thermal runaway. The contactor in the picture is a AC-rated unit. DC arcs do not extinguish naturally at zero-crossing as they do in AC. Using an AC contactor on DC can lead to welded contacts, sustained arcing, or fire.

Under SANS 10142-1:2020, Clause 7.12.4.5, all PV circuits must have switch-disconnectors and protective devices specifically rated for DC at the circuit voltage. An AC-only contactor does not meet this requirement. The setup omits proper DC fusing and isolation. PV strings must have individual DC-rated fuses, string isolators, and overcurrent protection per SANS 10142-1, Clauses 7.12.5.1 and 7.12.5.2. Without this, a fault or short circuit could result in high fault current from multiple panels that will not clear safely. Keeping the thermostat and control circuit at 230 V AC while the heating circuit operates on unregulated DC creates a mixed-voltage environment. This violates the basic separation and insulation coordination requirements in Clause 5.3.6 and Clause 6.1.6.1 of SANS 10142-1.

This type of modification would likely not pass a CoC inspection and could void household insurance in the event of fire or injury.

SANS 10142-1:2020 requires that all wiring, switching, and protective devices be correctly rated for the circuit type and voltage (Clause 6.1.5.1). Using AC components on DC circuits does not comply.

Use a PV diverter or dedicated DC-MPPT heating controller (there are several available locally) that manages voltage, current, and switching safely within SANS limits or, heat the geyser on the AC side using a properly rated AC contactor or relay controlled by your inverter or energy management system. This keeps all protection, RCD, and earthing arrangements fully compliant.

It’s great to see people experimenting with solar heating ideas, but wiring PV panels directly to an AC element without DC-rated components or protection creates significant fire and shock hazards and is not compliant with SANS 10142-1:2020.

Anyone planning to do this should use the correct DC-rated switching, isolation, and protection — or stick to an AC-side control method that’s proven safe.

1 hour ago, TaliaB said:

Response to @tony Lampard idea above:

I just want to raise a few safety and compliance points for the benefit of anyone considering a similar setup this isn’t meant as criticism, but to make sure people understand the risks and what’s required for a compliant installation.

Standard 230 V AC geyser elements are not designed for DC operation. PV panels produce variable DC voltage and current that change constantly with sunlight. Without proper regulation (MPPT or controller), the element and thermostat can be exposed to uncontrolled current and voltage. This can result in overheating, premature element failure, or thermal runaway. The contactor in the picture is a AC-rated unit. DC arcs do not extinguish naturally at zero-crossing as they do in AC. Using an AC contactor on DC can lead to welded contacts, sustained arcing, or fire.

Under SANS 10142-1:2020, Clause 7.12.4.5, all PV circuits must have switch-disconnectors and protective devices specifically rated for DC at the circuit voltage. An AC-only contactor does not meet this requirement. The setup omits proper DC fusing and isolation. PV strings must have individual DC-rated fuses, string isolators, and overcurrent protection per SANS 10142-1, Clauses 7.12.5.1 and 7.12.5.2. Without this, a fault or short circuit could result in high fault current from multiple panels that will not clear safely. Keeping the thermostat and control circuit at 230 V AC while the heating circuit operates on unregulated DC creates a mixed-voltage environment. This violates the basic separation and insulation coordination requirements in Clause 5.3.6 and Clause 6.1.6.1 of SANS 10142-1.

This type of modification would likely not pass a CoC inspection and could void household insurance in the event of fire or injury.

SANS 10142-1:2020 requires that all wiring, switching, and protective devices be correctly rated for the circuit type and voltage (Clause 6.1.5.1). Using AC components on DC circuits does not comply.

Use a PV diverter or dedicated DC-MPPT heating controller (there are several available locally) that manages voltage, current, and switching safely within SANS limits or, heat the geyser on the AC side using a properly rated AC contactor or relay controlled by your inverter or energy management system. This keeps all protection, RCD, and earthing arrangements fully compliant.

It’s great to see people experimenting with solar heating ideas, but wiring PV panels directly to an AC element without DC-rated components or protection creates significant fire and shock hazards and is not compliant with SANS 10142-1:2020.

Anyone planning to do this should use the correct DC-rated switching, isolation, and protection — or stick to an AC-side control method that’s proven safe.

Such modifications may work for years without issue, but all it takes is one incident to create a big mess for oneself.

I just went with a geyser controller that comes with certification, etc. It was only 2.7k. Allowed me to connect the 4 panels to the geyser element since it outputs a modified sine wave to the thermostat/element.

A properly rated DC contactor can even hit 1k in cost. It is just not worth it.